L1

Covering all the green-car bases at the 2009 Frankfurt Auto Show, Volkswagen unveiled not only the E-Up electric city car concept but also the L1, a radical 170-mpg tandem two-seat diesel hybrid streamliner it says it will sell by 2013. The L1 name refers to the European concept of a "1-Liter" car, meaning one so efficient it uses no more than 1.0 liters of fuel per 100 kilometers. If you're not particularly metric, that translates to 235 miles per gallon. VW didn't quite make its mark; the L1 actually uses 1.38 L/100 km, meaning its gas mileage is "only" 170 miles per gallon. To keep weight...